Is it possible we'll get DNR artifacts, plus the grain introduced with this Film Grain Technology?
ali wrote:
Thomson’s New Film Grain Technology™ as adopted by HD-DVD is here too...
http://www.videobusiness.com/article/CA6350773.html
SMPTE approves Thomson technology
Film Grain process part of HD DVD specs but not Blu-ray
By Paul Sweeting 7/7/2006
JULY 7 | Technicolor-parent Thomson has been given a stamp of approval for a technology to make high-definition video look more like conventional film during playback.
The Society of Motion Picture and Television Engineers last week formally adopted the technology by publishing the system’s specs on its Web site as a “registered disclosure document,†the engineering equivalent of the Good Housekeeping Seal of Approval.
The process, called Film Grain Technology, is already in use in HD DVD players and playback software. But the endorsement by SMPTE paves the way for broader adoption as high-def video becomes more entrenched both in the movie production process and home entertainment formats.
“Thanks to our relationship with Technicolor, we have access to a lot of people in Hollywood, including many of the top ‘golden eyes’ at the studios,†the head of Thomson’s Corporate Research Center, Jeff Cooper, said. “We were very happy to be able to fool several of the top people in the field, who couldn’t tell the difference between original film and the video using our technique.â€
Typically, the “grain†that naturally occurs in film emulsions is removed in transferring a film to video, giving video a somewhat “flat†or artificial look compared with film.
Thomson’s Film Grain Technology inserts a simulated grain pattern into a video signal before display to restore some of the richness and texture lost during the transfer.
“With standard-definition and ordinary TV displays, you can’t really resolve grain, so there was no point in trying to keep it,†Cooper said. “But with HDTV sets, you have a device that can preserve and display the original grain if you can get it there. Although it’s still a problem to get the original grain to the display, we can preserve the look of the original so what you’re seeing looks more like a projected film image.â€
Unlike actors and other solid objects in a film scene, the grain pattern in film is random from one frame to another. That makes its difficult to encode using standard compression schemes, which rely on predicting the content of one frame as much as possible from the frame before.
Without such predictability, the grain pattern for each frame would have to be encoded separately, which would consume much of the bandwidth or storage capacity available with current video formats, even given the increased capacity of HD DVD and Blu-ray Disc.
As a result, grain is usually removed to leave bits available for image detail.
Although grain is still removed in the Thomson process, FGT developers used mathematical models of particular film grains to create simulated grain patterns.
The simulated pattern is then pumped back into the video just before it’s displayed.
“People have been modeling film grain and developing simulations for years, so there was a large body of knowledge to draw on there,†Cooper said. “The key was to come up with ways of modeling that could accommodate all, or at least many, of the variety of film stocks that directors use to achieve the effect they want, and then make it simple enough to implement in consumer devices.â€
With SMPTE approval, the FGT also is likely now to find a role in the production process as well, Cooper said. “A lot of movies today are a combination of traditional film and CGI, which does not contain grain. This is a convenient way to give the entire film a consistent look.
Thomson proposed the technology to the DVD Forum in early 2005, which adopted it as a mandatory feature of the HD DVD specifications.
The technology also was offered to the Blu-ray Disc Assn. but was not adopted for that format.
Cooper declined to comment on the reasons behind the Blu-ray group’s decision.
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